(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x-7\right)\left(x-9\right)$
$\left(x-6\right)\left(x-1\right)$
$\left(-x+6\right)\left(9+x\right)$
$\left(-x+4\right)\left(9+x\right)$
$\left(4+x\right)\left(x-2\right)$
$\left(-1+x\right)\left(x-2\right)$
$\left(-4+x\right)\left(4-x\right)$
$\left(-7+x\right)\left(-9+x\right)$
$\left(x-7\right)\left(-8x+1\right)$
$\left(8x+5\right)\left(2x-5\right)$
$\left(-9x+8\right)\left(1+2x\right)$
$\left(4x-1\right)\left(-3+8x\right)$
$\left(-3+5x\right)\left(5x-6\right)$
$\left(8+x\right)\left(x+9\right)$
$\left(-3+5x\right)\left(7+2x\right)$
$\left(-2+9x\right)\left(1+3x\right)$